It all depends on how you plan to cook the protein, and how good a cook you are.
The net effect of injecting a salt-water solution is virtually same as brining it.
I am not strongly opposed to brining a turkey breast, as (if done correctly) this will result in a juicy bird without the necessity of trying to brine a 16-20 pound turkey! For pork, some cuts can benefit from this (if you cook it appropriately), while others will be ruined. In general, I'd rather buy chicken breasts at Fresh Market, Whole Foods, et al than Kroger injected, although again it depends on the specifics of the recipe. For beef, I would NEVER purchase injected meat as you normally would want aged meat, in which the beef actually dries out prior to cooking!
For Kroger, they obviously will make 15% more money on the proteins that are injected. Also, if asked about it, they can make a case that for the average home cook (who tends to over-cook everything) the injected meats actually make for juicier and more flavorfull dishes.